says bank 1&2 are lean i just changed the o2 sensors front and back ...
what else can it be? My next guess would be mass air flow.any help would be appreciated.I do know that in the morning when i turn the truck on,the truck runs a little rough at start up then runs fine after a few seconds

 

ttt

 

it may be a bad cat also.

 

vaccum leak

 

how would go about checking if one of those are the problem?

 

Check and make sure all you vacuum hoses are going somewhere and look for cracked or broken hoses. Or listen for a leak.

 

My dads 99 4.0 OHV was doing the same thing. I tried all the normal stuff but what fixed it was replacing the "plenum" gaskets. The rubber inserts that go into the plastic upper intake looked like they had flattened out over time and was letting unmetered air into the intake.